Speed-governor.



A. D. SKINNER.

SPEED GOVERNOR.

APPLICATION FILED DEC.29. 19w.

Patefited Dec. 10, 1.918.

3 SHEETS-SHEET ll I T N ESS E S 26%. a. [gVlfNTOR BY im Q4 TTO/HVE Y.

A. D. SKINNER.

SPEED GOVERNOR.

APPLICATION FILED DEC.29, I917.

D Patented Dec. 10, 918.

3 SHEETSSHEET 2- ALLAN D. SKINNER, OF ERIE, PENNSYLVANIA.

SPEED-GOVERNOR.

Specification of Letters Patent.

Patented-Dec. 10, 1918.

Application filed December 29, 1917. Serial No. 209,427.

To all whom it may concern: I

Be it known that I, ALLAN D. .SKINNER, a citizen of the United States,residing at'Erie,

in the county of Erie and State of Penna,

automatic governorfor controlling admis-' sion valves and it may beapplied to steam or other engines. An automatic governor will controlthe operation of an engine within certain limits, but for some classesof service, such as where the engines are operating compressors, pumpsor fans, it is desirable and necessary at times to vary the speed of theengine according to the desired output of the compressor, pump or fan,beyond. the range of the ordinary automatic governor.

Heretofore this has ordinarily been done in various ways which areobjectionable in some respects, suchas by various hand operated cutoffs,or by stopping the engine and changing the weights or tension of thesprings of the governor,- or by the use of a throttling governor. p

The present invention provides means for varying the speed within ratherwidelimits, and according to the load, said means being additional to,and in some respect independent of, the ordinary or normal governormechanism. i

- The invention requires no more valve gear than a shaft governorengine" built for constant speed, and has a further advantage that itoperates while the engine is running, being supplemental to the normalaction of the governor.

The invention embodies the use, in one of its forms, of an electricmotor, which iscarried by the governor and which is controlled bydevices actuated according to load or desired conditions, to Varytheposition of the lever arm of the governor, to thereby vary or shift thevalve operating mechanism and accordingly the valve travel.

The invention also involves certain improved details of construction aswill be more fully apparent from the following description.

In the accompanying drawings,

Figure 1 1s a diagram of the controlling system applied to an engine anda pump.

Fig. 2 is a side ele ation of the shaft governor with parts of theinvention applied thereto.

Fig. 3 is a section of the line 33 of Fig. 4 is an enlarged detail ofthe bearing of the governor arm.-

Fig. 5 is a section showing the pressure controlled switch whichcontrols the circuits of the electric motor. s I

Fig. 6 is an end view of Fig. 5.

Referring specifically to the drawings, A indicates an engine and B arotary pump driven thereby; C is a fly wheel and D is a belt therefromto the pump. The valve gear has been omitted from the drawing but itwill be understood that the engine is provided with such gear as usual,this gear being operated by the shaft governor which is mounted on thefly wheel C as shown in Fig. 2. Although illustrated in connection witha pump, the invention could be used in connection with a fan or anyother load, no limitation in this respect being implied.

The governor arm is indicated at 6 mounted on the wheel C by thesuspension pin 7, and the outer end of this pin is hollowed to receivethe hub 8 of the eccentric arm 9 which is held on the pin by a bolt 10.

Roller bearings 11 may be used between the pin and the arm if desired.The arm 6 carries the Weights 12 and 13 and is con-' nected to thegovernor spring 14 which is attached to the governor wheel in the usualmanner, but not shown, these parts being of standard type, such forexample as shown in the patent to Skinner No. 628591.

15 is a long travel stop on the wheel for the governor arm 6, and '16 isthe short travel stop for-"the 'same,

The eccentric arm 9 carries a pin 17 which is connected to and'operatesthe admission valve gear (not shown) in the usual manner. This arm hasheretofore formed an integral part of the governor arm 6, but in thepresent invention this arm may be moved angularly relative to the saidarm 6, whereby the valve travel may be varied independently of orsupplemental to the position of the governor arm, the eccentric armbeing (except when its position is varied by the m o tor') locked inrelation to the governor arm.

This relative variation in the angularity of the two arms isaccomplished by an electric motor 18. This motor is mounted on a bracketon the governor armand its armature, is connected or geared to anon-traveling'screw 19 which is supportedby a suitable bracket 20 on thearm. 21 1s a nut-or threaded block which travels on the screw '19,andthis nut is connected by a link 22 to the end of the eccentric arm 9as shown opposite the Wrist pin 17. It will be seen that the angularrelation of thearms 9 and 6 may be varied by rotation of the screw bythe motor, the nut 21 traveling along the screw 1 pin 17 independent ofany variation inci-- dent to the posit on and thereby varying theeccentricity of the of the main governor tl-Tm 6. l L- This motor isWired as indicated at 23 to I collector rings 24 on the hub of the flywheel,

and these rings receive current from brushes 25 which are preferablvconnected by wiring 26 to relays 27 and 28 in the high voltage line 29.The wiring is so arranged that the motor 18 can'be reversed, one of. the.re- 7 lays being connected to give the direct drive and theother togive the reverse. drive, and these relays are preferably connected to alow voltage line 30 whichcontains a circuit changer or switch indicatedat 31 controlled by a pressure actuated device lndlcated at 32 which iscontrolled by pressure or other load, conditions. I

In the device illustrated for thepurpose of this description, thecontrolling device- 32 comprises a cylinder containing a piston 33pressed in one direction by a spring :54, and carrying a sliding switchpiece 35 with a cross bar 36 01. conductingmaterial which" closes thepairs of terminals 37 and 380mnected respectively to the relays 27 and28;

- or the switch bar may rest in'neutral position between the two pairsof terminals. On

the side of the piston opposite the spring the cylinder is connected bya pipe 39 to the outlet pipe 40 from the pump B, whereby the. piston issubjected to the discharge.

*the eccentric pin 17 to the long travel position, as usual in governorsof this type. WVhen. the engine isstarted the arm will remain in saidposition until the engine reaches'a predetermined speed, whereupon thecentrifugal action cau'ses it to leave the;

' stop 15, giving-a constant speedirrespective of the load, within themaximum capacity of the engine, and. when the engine carries no load butits own friction, the governor arm will swing toward-or agalnst the stopi 16. This is the standard operation of a governor of this type, whichthus provides a limit to the'speed of the engine, -As stated above,under certain condltlons it .is desirable t reduce thespeed of theengine below the set speed of the ordinary automatic governor.

' Thus should it bedesired to reduce the speed by means of the separatecontrol the switch 31 may be operated to close the circuit of the motor18 and drive'the same in such direction as to draw the block 21 towardthe motor, and toward the right as swing the arm 9 relative to the arm 6and to-shift the wrist pin 17 toward the short travel position. In otherwords it varies the relation between the valve gear and the shownin Fig.2, and the effect of this is to governor arm 6. This action would otherwise result in the shortening of the valve travel, thereby decreasingthe speed of the engine, but is automatically compensated for by thegovernor arm 6 assuming anew position nearer the 'stop 15. That is tosay, the if normal action of the governor,- tending to keep the engineat constant normal speed'for which it was set, causes the lever 6 toassume a new. position nearer the long travel stop 15-and the pin 17 isthereby held in the same eccentric relation to the shaft as it wasbefore the adjustment was made. Then by still further shifting theeccentric arm 9 in the direction stated, the governor arm 6 will finallyrest against the stop 15, and

a further shifting of the arm 9 toward the short travel position can nolonger be compensat-ed by further movement of the arm 6, and thereforethe speed of the engine will necessarily be reduced by the shortenedvalve travel, admitting less steam to the engine. In other words, afterthe lever 9 has reached the stop 15, the normal action of the governorhas been overcome and further movement of the arm 9 in the directionstated results in shortening the valve travel and reducing the speed.Should the load of the engine be sufliciently reduced or. removed whenthe eccentric arm 9 is in the position just described the engine willspeed up until it reaches the speed to whlch the governor is set,where'- upon the governor arm 6 will leave the stop 15 by reason of theusual c ei'itrifugalaction, and the eccentric .arm 9 willswing withthegovernor armtoward the short travel positionuntil the steam admittedcorrespondsto the reduced load, when the Farms will. resume their usualfunction and will act as a speed limit stop.

lVhen the engine is running at the reduced speed should it be necessaryor desired to increase the speed of the engine, the

control switch 31 will be shifted in the opposite direction from thatabove explained, and by the electrical connections the motor 18 will bedriven in a direction to shift the block 21 to the left in'Fig. 2 andthe effect of this willbe to swing the eccentric pin 17 toward the-longtravel position, thereby increasing the valve travel and the speedaccordingly, in almanner the reverse of that described above, until theengine obtains the speed for which the governor Was set, whereupon thegovernor arm leaves stop and the governor resumes its normal functions.In order to prevent any increase of speed abovethat to which thegovernor is set, the bracket 20 is so located that it acts as a stop forthe movement of the block 21 to the left in Fig. 2, similarly to thestop 41 with respect to movement to the movement in that direction, soas to avoid burning out the motor.

It maybe stated here that the eccentric arm 9 has an extension 9 on theouter end thereof, and the wheel 0 has a stop 41 for said extension,which is so placed, that when the arm 9 is in its position'of leasttravel, the extension 9 will stopagainst the part 41 and will preventthearin- 9' from swinging beyond the least travel position into aposition which would reverse the direction ofrotation of the engine.That is, assuming that the-engine is operating at a speed less than themaximum speed to which the ,governor' is adjusted, and assuming that thearm has been moved toward the short travel position, if the load shouldbe reduced or thrown off entirely the arm 6 wo'uldimmediately swingtoward-the short travel stop 16, which, were it not preventedby theextension 9 striking the stop 41 in advance might throw the eccentricarm into sulting in reversing the engine.

It will-be seen that by means of this device the speed of the engine maybe varied as desired below the normal speed for which the governor isset; that the engine cannot be reversed in its rotation, and that its-'a position beyond the shortest travel, re-

speed cannot be increased beyond the limit to which the governor isadjusted.

It will be appreciated that the controlling switch may be operated byhand, or it may be operated by the automatic device illustrated, or byother automatic device controlled by pressure, volume or velocity offluids actuated by a machine driven by the engine.

when the pressure admitted through ,the pipe 39 exceeds thetension ofthe spring 34 the piston will be driven to the right until lay 28 themotor will be driven in such a direction as to reduce the speed of theengine and consequently the work of the pump. And in likef manner, ifthe discharge pressure of the pum decreases to such an extent that thespring shifts the switch to the other position, as shown in Fig. 5, thecontacts 37 will be closed, operating the relay 27 and driving the motor18 in the reverse direction, thereby shifting the arm 9 and increasingthe speed of the engine and the work of the pump. The spring 34 will beadjusted according to the pressure desired so that, normally, the switchwill be in neutral position, with the connector 36 in the space betweenthe terminals 37 and 38. The positionof the said terminals may beadjusted by the screws 50 so as to increase or decrease the gap betweenthe terminals and thus permit as much variation in pressure as desired,before the motor comes into operation.

The relays might be omitted-and the motor circuits connected directly tothe switch, but relays are preferable where high voltage is used. It; isto be understood that the adjustment of the movable eccentricv arm maybe effected by an electric motor, a fluid with the shaft one of whichis.adapted for attachment to a valve gear, of means to adjust saidconnection to vary the relative a'n-Q gularity of the levers.

- 2. The combination with a shaft governor including two connectedlevers revolving with the shaft one of which is adapted for attachmentto a valve gear, of means to adjust said connection to vary the relativeangularity of the levers, said means including an electric motor carriedby one of the levers and 'operatively connected to the other.

3. The combination with a shaft governor including a weighted governorarm' and an eccentric arm revolving with the shaft, said arms beingpivotally mounted with respect to each other, of electrically operatedadj ustin'q' devices connecting the two arms and operable to vary therelative angularity of the arms.

4. The combination with a governor including a weighted governor arm andan cecentric arm, said arms :being pivotally mounted with respect toeach other, of an electric motor mounted on one of the arms, Thus in thecontrolhng device illustrated,-

a screw drlven by the motor and operatively connected to the other arm,and means to 6. The combination with a shaft governor mechanismincluding an eccentric arm adapted for connection to a valve gear, of amodifying mechanism including an electric motor carried by the governorand operatively connectedto said arm to vary the angularity thereof,circuit connections to said I motor, including a rotary collector, and aswitch in said circuit, and means automatically actuated by the load onthe engine to operate the switch.

1 7. The combination with a shaft governormechanism including aneccentric arm adapted for connection to a valve gear, of a modifyingmechanism therefor including a reversible electric motor carried by thegovernor and operatively connected to one of the governor parts to varythe angularity thereof, circuit connections to said motor,

and a reversing switch in said circuit connections, and meansautomatically controlled by the load on the engine to operate theswitch.

8. The combination with a shaft governor including two connected leversrevolving with the shaft one of which is adapted for attachment to avalve gear, of means to -au-' tomatically adjust the angularlty of oneof the levers with respect to the other,-and a stop engageable by theadjustable lever to limit the extent of its adjustment.

In testimonywhereof, Iatfix my signature in presence of two, witnesses.

ALLAN D. SKINNER.

Witnesses: ALBERT E. ROSE,

GEO. E. TEW.

